I recently had the head replaced on a 4.0 01 Wrangler due to the 0331 issues. Spark plugs were changed as well. However now the check engine light is coming on with longer distance travels. Does not flash, just illuminates. I pulled the codes and they are P0304, P0305, P0306, and P0300. The engine does not seem to misfire and I was traveling 70-75 without much issues. I have driven it around 300 miles since the head replacement. The light does not come on with shorter distance driving around town, only 1-2 hour drives. It was a brand new head from Clearwater as well. Any help would be greatly appreciated!